1. Field of the Invention
This invention relates to a gas distribution manifold arrangement and methods for the gas precharge of a plurality of hydropneumatic hydraulic accumulators, and to the combination of such gas distribution manifold arrangement with a gyratory crusher having associated therewith a plurality of hydropneumatic hydraulic accumulators.
2. Description of the Prior Art
It is well known in the prior art relating to gyratory crushers of the type using hydraulic means for supporting the mainshaft on which the crushing head is attached or otherwise supported to provide means for lowering the crushing head and the supporting shaft thereof when uncrushable material such as "tramp iron" enters the crushing chamber, whereby to permit the crusher to pass the "tramp iron." "Tramp iron" is a term used in the art to designate an uncrushable object such as a metal dipper tooth or the like, for example, which is foreign to the mineral ore being processed by the crusher. The tramp iron relief is provided by conducting the hydraulic liquid beneath the piston which supports the crusher mainshaft to a hydraulic accumulator whereby the mainshaft and the crushing head supported thereby are lowered to permit passage of the tramp iron or the like through the crusher. The hydraulic means for supporting the crusher shaft also permits lowering of the crusher shaft when other operating conditions are encountered, such as, for example, packing of wet material in the crusher, or the presence of tree limbs or the like in the crushing chamber. Examples of prior art patents showing the use of hydraulic accumulators for the purpose just mentioned in connection with gyratory crushers are U.S. Pat. No. 2,579,516 issued to Alexander J. Roubal on Dec. 25, 1951, and U.S. Pat. No. 2,667,309 issued to George D. Becker on Jan. 26, 1954.
In the case of large gyratory crushers, having a hydraulic cylinder of large capacity associated with the crusher mainshaft, it is known in the prior art to provide a plurality of hydraulic accumulators which are hydraulically connected in parallel hydraulic flow relation with each other to a hydraulic accumulator manifold, which, in turn, is hydraulically connected to the hydraulic cylinder associated with the gyratory crusher.
One well known form of hydropneumatic hydraulic accumulator includes an outer shell defining a hollow chamber, wih an elastic bladder positioned within the hollow chamber, the interior of the elastic bladder being adapted to receive through a suitable inlet valve means at one end of the accumulator shell a precharge of a suitable pneumatic or gaseous fluid such as gaseous nitrogen, air, or the like. The opposite end of the accumulator shell is provided with an inlet means adapted to receive a hydraulic liquid whereby to relieve an excess hydraulic pressure condition in the system to which the hydraulic accumulator is connected. The hydraulic liquid received within the accumulator shell causes compression of the gas-filled elastic bladder, and when the excessive hydraulic pressure condition no longer exists in the system to which the accumulator is connected, the compressed bladder ejects the hydraulic liquid from the accumulator shell and returns it to the system to which the accumulator is connected.
Another well-known type of hydropneumatic hydraulic accumulator is the "floating piston" type of accumulator in which a precharge of pneumatic fluid is confined within the accumulator shell or piston chamber on one side of the floating piston, and the hydraulic fluid is introduced into the accumulator shell or piston chamber on the opposite side of the floating piston.
When an assembly of a plurality of associated hydropneumatic hydraulic accumlators is provided, as, for example, to provide hydraulic relief for a large gyratory crusher, as previously mentioned, each hydraulic accumulator is provided with a precharge of pneumatic fluid such as nitrogen gas, which pneumatic precharge in case of the common forms of hydraulic accumulators previously described, is received in the corresponding elastic bladder positioned within the respective accumulator shell, in the case of the bladder type of accumulator, and is received on one side of the floating piston in the case of the "floating piston" type of accumulator.
In the prior art, where a plurality of hydraulic accumulators were provided in association with each other to provide hydraulic relief to a hydraulic system such as that of a gyratory crusher, the usual practice was to individually charge each accumulator with the precharge of pneumatic fluid such as nitrogen. This prior art method in accordance with which each accumulator was individually charged with pneumatic fluid has various disadvantages which it is an object of the present invention to overcome. One disadvantage of this prior art method just referred to was that the various accumulators of the plurality of associated accumulators did not always have equal pneumatic charges, with the result that one accumulator of the plurality, namely, the accumulator having the lowest pneumatic charge, would constantly cycle and fail.